21–25 Sept 2015
Laboratori Nazionali di Frascati
Europe/Rome timezone

Contribution List

81 out of 81 displayed
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  1. 21/09/2015, 08:00
  2. 21/09/2015, 08:45
  3. Mauro Anselmino (TO)
    21/09/2015, 09:00
    Invited talk
    1.
    The Transverse Momentum Dependent Partonic Distributions (TMD-PDFs) and Fragmentation Functions (TMD-FFs) should reveal new properties of the 3-dimensional structure of nucleons and of the quark hadronization process. Many experimental data are now available and much progress has been made in their phenomenological interpretation. A short summary of the situation is presented.
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  4. Abhay Deshpande (Stony Brook University)
    21/09/2015, 09:30
    Invited talk
    1.
    Deep Inelastic Scatting is arguably the best experimental technique employed by physicists to study the fundamental structure of nucleons and nuclei. Much of what we know about the quark gluon structure of the nucleons and nuclei comes form experiment performed in polarized and unpolarized fixed-target experiments around the world, and those performed at DESY using the HERA collider. However...
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  5. Dr Cedric Lorce (IPNO and LPT Orsay, Universite Paris-Sud)
    21/09/2015, 10:00
    Invited talk
    1.
    The orbital angular momentum of quarks and gluons contributes significantly to the proton spin budget and attracted a lot of attention in the recent years, both theoretically and experimentally. We summarize the various definitions of parton orbital angular momentum together with their relations with parton distributions functions. In particular, we highlight current theoretical puzzles and...
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  6. Prof. Matthias Burkardt (New Mexico State University)
    21/09/2015, 10:30
    1.
    Definitions of orbital angular momentum based on Wigner distributions are used to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. The difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that...
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  7. Dr Dieter Mueller (Ruhr-University Bochum)
    21/09/2015, 11:45
    2.
    We introduce a classification scheme for parton distribution models and we model generalized parton distributions (GPDs), their form factors, and parton distribution functions (PDFs), integrated and unintegrated ones, in terms of unintegrated double distributions that are obtained from the parton number conserved overlap of effective light-cone wave functions. For a so-called "spherical"...
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  8. Dr Jonathan Gaunt (DESY)
    21/09/2015, 12:15
    Invited talk
    2.
    Double parton scattering (DPS) is the process in which two distinct pairs of partons hard scatter in an individual proton-proton collision. It can be an important background to single scattering processes suppressed by small or multiple coupling constants (e.g. new physics signals), and can reveal novel information about the proton structure. I review recent developments in the endeavour to...
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  9. Wojciech Broniowski (Jan Kochanowski U. and Institute on Nuclear Physics PAN, Poland)
    21/09/2015, 12:45
    Oral contribution
    2.
    We explore ansatze for parton distributions of the proton following the idea of the valon model, where the Fock components have the form f1(x_1)f1(x_2)...fn(x_n)delta(1-x_1-x_2-...-x_n). Upon integration, double and single parton distributions are generated from the n-particle distributions. We show that the construction leads to preservation of the Gaunt-Stirling sum rules, thus providing...
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  10. Prof. Guy de Teramond (University of Costa Rica)
    21/09/2015, 14:30
    Invited talk
    3.
    Relativistic bound-state equations for mesons and baryons are constructed in a semiclassical approximation to light-front QCD from a superconformal algebra which relates baryon and meson spectra. This procedure uniquely determines the confinement potential for arbitrary spin and its embedding in AdS space. The specific breaking of dilatation invariance within the supersymmetric algebra...
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  11. Dr Joannis Papavassiliou (Universtiy of Valencia)
    21/09/2015, 15:00
    Invited talk
    3.
    One of the longstanding challenges of QCD is to furnish quantitatively accurate ab-initio predictions for the observable properties of hadrons. In this talk we present a significant step for bridging this gap, based on the synergy between Schwinger-Dyson equations and large-volume lattice simulations.
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  12. Prof. Stanislaw Glazek (University of Warsaw)
    21/09/2015, 15:30
    Oral contribution
    3.
    Ridge-like correlations in high-energy proton-proton collisions reported by the CMS collaboration suggest a collective flow that resembles the one in heavy-ion collisions. If the hydrodynamic description is valid then the effect results from the initial anisotropy of the colliding matter, which depends on the distribution of matter in protons. Following recent theoretical...
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  13. Matteo Rinaldi (PG)
    21/09/2015, 16:30
    Oral contribution
    4.
    We present a calculation of the effective cross section σ_eff , an important ingredient in the theoretical description of double parton scattering in proton-proton collisions. The theoretical approach makes use of a Light-Front quark model as framework to calculate the double parton distribution functions at low-resolution scale. QCD evolution is implemented to reach the experimental...
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  14. Dr Dipankar Chakrabarti (Indian Institute of Technology Kanpur, India)
    21/09/2015, 16:50
    Oral contribution
    4.
    In lightcone framework, longitudinal angular momentum operator is kinematical but the transverse angular momentum operator is dynamical and thus understanding the transverse spin and transverse angular momentum of the proton is more complicated than longitudinal spin and angular momentum and frame dependent. Here, we evaluate the gravitational form factors for a transversely polarized...
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  15. Jose Osvaldo Gonzalez Hernandez (TO)
    21/09/2015, 17:10
    Oral contribution
    4.
    The role of TMDs in understanding the 3D-structure of hadrons has drawn a lot of interest in both the theoretical and experimental communities. In order to extract TMDs, it is necessary to understand what information is contained in the different sets of data that are available. In this talk, I will discuss the advantages and limitations of some of the most recent experimental data, in the...
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  16. Ms Sabrina Cotogno (Vrije Universiteit Amsterdam and Nikhef)
    21/09/2015, 17:30
    Oral contribution
    4.
    The Light-Front Wave Functions (LFWFs) represent a perfect starting point for describing the partonic structure of hadrons. In this work we use the results for the LFWFs of the pion coming from the AdS/QCD correspondence, in the context of a soft-wall model. We study the parton distribution function (PDF) and the electromagnetic form factor (FF) of the pion and for the first time we implement...
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  17. Mr Arkadiusz P. Trawinski (University of Warsaw)
    21/09/2015, 17:50
    Oral contribution
    4.
    An approximate light-cone wave function for the pion effective quark-antiquark Fock sector corresponding to a small value of the renormalization group parameter $\lambda$ will be presented. This wave function will be used to obtain wave functions of higher pion sectors for larger $\lambda$ by the W-transformation [1]. The approximate wave function is motivated by the LF-holography [2] in...
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  18. Mr CHANDAN MONDAL (INDIAN INSTITUTE OF TECHNOLOGY KANPUR)
    21/09/2015, 18:10
    Poster Session
    We present the nucleon electromagnetic form factors, using the light-front wave functions of a quark-diquark model for the nucleon predicted by the soft-wall model of AdS/QCD. The results are compared with the soft-wall AdS/QCD model. Then we show a comparitive study of the nucleon charge and anomalous magnetization densities in the transverse plane. Flavor decompositions of the form factors...
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  19. Dr Elżbieta Dzimida-Chmielewska (University of Bialystok)
    21/09/2015, 18:10
    Poster Session
    The LC gauge condition A_0-A_3=0 is considered within the canonical quantization procedure with different temporal parameters: x^0, x^+ and x^-, respectively. Though this gauge condition is Lorentz noncovariant, the symmetry for the Lorentz boost along the x^3 axis remains unbroken. This longitudinal boost plays a crucial role for the modified quantization procedure at the hypersurface...
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  20. Jorge Sales (Universidade Estadual de Santa Cruz, DCET-PPGMC)
    21/09/2015, 18:10
    Poster Session
    The generalized elecrodynamics proposed by Podolsky is based on the Lagrangian density \begin{equation*} {\cal L}_{\text{o}}=-\frac{1}{4}F^{\mu \nu }F_{\mu \nu }+\frac{a^{2}}{2}\partial _{\nu }F^{\mu \nu }\partial ^{\lambda }F_{\mu \lambda }, \end{equation*}% in which $a$ is a constant with dimension of length. This Lagrangian density generates a linear field theory, with gauge symmetry...
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  21. Dr Jan Żochowski (University of Białystok)
    21/09/2015, 18:10
    Poster Session
    A novel quantization procedure with the explicit Lorentz symmetry is applied for a fermion field in $D=3+1$ dimensions. The Wightman function for a free fermion field is evaluated in terms of the covariant singular function $\Delta_{+}(x)$. The singularities at the LF hypersurface $x^{+}=0$ appear whenever the "bad" component $\psi_{-}$ is considered. Accordingly the anti-commutator function...
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  22. Loredana Bellantuono (BA)
    21/09/2015, 18:10
    The spectrum of the glueball with $J^{PC}=0^{--}$ is computed using different bottom-up holographic models of QCD. The results indicate a lowest-lying state lighter than in the determination by other methods, with mass $m \simeq 2.8$ GeV. The in-medium properties of this gluonium are investigated, and stability against thermal and density effects is compared to other hadronic systems....
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  23. Mrs Clayton Santos Mello (Instituto Tecnológico de Aeronáutica)
    21/09/2015, 18:10
    Poster Session
    In this work, we study the pion valence wave function by starting with an analytic parametrisations of the vertex function and running quark mass fitted to lattice-QCD results. We also investigate the pion electromagnetic structure of the pion, which is a pseudoscalar meson composed of a quark-antiquark bound state, i.e., $|u \ \bar{d}>$ with total spin zero and negative parity. Our...
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  24. Loredana Bellantuono (BA)
    21/09/2015, 18:10
    Poster Session
    Methods based on the gauge/gravity duality are useful tools for the study of strong interactions phenomenology. In particular, the holographic approach seems effective in describing relaxation processes of strongly coupled systems, taken initially out of equilibrium. I examine the case of a boost-invariant fluid, focusing on the production of a far-from-equilibrium configuration and on the...
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  25. Prof. Szczepaniak Adam (Indiana University and Jefferson Lab)
    22/09/2015, 09:00
    Invited talk
    5.
    Hadron spectroscopy plays an important role in determining workings of QCD. I will discuss recent developments in theory and phenomenology and the emerging challenges and opportunities given the forthcoming high precision data from the Jefferson Lab and other facilities.
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  26. Dr Sinead Ryan (Trinity College Dublin)
    22/09/2015, 09:30
    Invited talk
    5.
    I will review recent progress in lattice hadron spectroscopy with an emphasis on resonances and scattering states. New theoretical ideas will be discussed and results from heavy and light quark systems presented. Some challenges and puzzles in hadron spectroscopy will be highlighted.
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  27. Raffaella De Vita (GE)
    22/09/2015, 10:00
    Invited talk
    5.
    Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to the force that binds them. Studying the hadron spectrum is therefore a...
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  28. Marco Bochicchio (ROMA1)
    22/09/2015, 10:30
    Invited talk
    5.
    We work out the constraints that the renormalization group imposes on two- and three-point, and certain multi-point correlators and S-matrix amplitudes, in large-N QCD and, more generally, in any large-N confining asymptotically free gauge theory. We construct a twistorial string theory that implies the QCD large-N glueball and meson spectrum and collinear S-matrix, that satisfies the...
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  29. Dr Jorge Segovia (University of Salamanca)
    22/09/2015, 11:45
    Invited talk
    6.
    The elastic and transition form factors of nucleon excited states provide vital information about their structure and composition. They are a measurable and physical manifestation of the nature of the hadrons' constituents and the dynamics that binds them together. In this respect, two emergent phenomena of Quantum Chromodynamics (QCD), confinement and dynamical chiral symmetry breaking,...
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  30. Dr Simona Malace (Jefferson Lab)
    22/09/2015, 12:15
    Invited talk
    6.
    The intriguing phenomenon of quark-hadron duality reflects the non-trivial relationship between observables at low energies in the region dominated by resonances and those in the deep inelastic scattering regime: averaged over the appropriate energy intervals the behavior of low-energy observables mimics that of high-energy, deep inelastic scattering ones. Quark-hadron duality has been...
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  31. Prof. Teresa Pena (IST Lisboa)
    22/09/2015, 12:45
    Invited talk
    6.
    We use the Covariant Spectator Theory (CST) \cite{FG}, which can be viewed as a reorganization of the Bethe-Salpeter equation (BSE) that works in Minkowski space, to develop a dynamical quark model that can describe the structure and the mass spectrum of both, heavy and light quark systems. We study mesonic structure and spectra. Treating mesons as effective qq states, our focus is on the...
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  32. Michele Viviani (PI)
    22/09/2015, 14:30
    Invited talk
    7.
    The inhomogeneous Bethe-Salpeter Equation for an interacting system, composed by two massive scalars exchanging a massive scalar, is numerically investigated in ladder approximation, directly in Minkowski space, by using an approach based on the Nakanishi integral representation. In this contribution, the results obtained for the scattering lengths and phase-shifts will be presented and...
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  33. Prof. Vladimir Karmanov (Lebedev Physical Institute)
    22/09/2015, 15:00
    Invited talk
    7.
    In the framework of the Light-Front Tamm-Dancoff method, we applied the sector-dependent renormalization scheme to the quenched Yukawa model. A review of the results obtained in this way is given. The Yukawa model incorporated spin is studied in the truncation N=3 (one fermion and two mesons), whereas the spinless Yukawa model is truncated up to a higher value N=4. The eigenvector...
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  34. Prof. Wayne Polyzou (The University of Iowa)
    22/09/2015, 15:30
    Invited talk
    7.
    We use algebraic methods to reconcile the triviality of the vacuum in different light-front field theories with the inequivalence of vacuua in different canonical theories. We show how the inequivalence arises by extending the vacuum functional from the light-font Fock algebra to the algebra of local observables. This extension leads to an identification of a sub-algebra of the...
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  35. Dr Maria Gomez-Rocha (University of Graz)
    22/09/2015, 16:30
    Oral contribution
    Asymptotic freedom of gluons in QCD is obtained in the leading terms of their renormalized Hamiltonian in the Fock space. We calculate the three-gluon interaction term in the front-form Hamiltonian for gluons using the renormalization group procedure for effective particles (RGPEP). The resulting three-gluon vertex is a function of the scale parameter, $s$, that has an interpretation of the...
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  36. Prof. Enrique Ruiz Arriola (Universidad de Granada)
    22/09/2015, 16:30
    Oral contribution
    We analyze the usefulness of the optical potential as suggested by the double spectral Mandelstam representation at very high energies. Its particular meaning regarding the analysis of Nucleon-Nucleon scattering data up to the maximum available measured energies and implications in heavy-ions collisions is also discussed.
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  37. Mr Wayne de Paula (Instituto Tecnológico de Aeronáutica)
    22/09/2015, 16:50
    Oral contribution
    We use the Nakanishi Integral Representation to solve the Bethe-Salpeter equation for two fermions bound state with a scalar exchanging, in Minkowski space. In this formulation we use the Light-Cone projection to obtain an equation for the Nakanishi weight function. Further, we investigate the validity of the Nakanishi uniqueness theorem for the weight functions for the Fermions system.
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  38. Luca Mantovani (PV)
    22/09/2015, 16:50
    Oral contribution
    We study the electron at order alpha as a system composed by an electron and a photon within the framework of light-front quantization. We derive the leading-twist transverse-momentum dependent distribution functions for both the electron and photon in the dressed electron, using different gauge prescriptions. In particular, we discuss the light-cone gauge and the Feynman gauge, applying both...
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  39. Dr Alfredo Vega (Universidad de Valparaiso)
    22/09/2015, 17:10
    Oral contribution
    Based on the matching of soft wall AdS / QCD models and Light - Front QCD for electromagnetic form factors, we derive a phenomenological wave function for hadrons with arbitrary twist dimension. We discuss a couple of examples of hadron properties calculated with this wave function.
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  40. Prof. Ho-Meoyng Choi (Kyungpook National University)
    22/09/2015, 17:10
    Oral contribution
    Hadronic distribution amplitudes (DAs) provide essential information on the QCD interaction of quarks, antiquarks and gluons inside the hadrons and play an essential role in applying QCD to hard exclusive processes such as the pion-photon transition form factor (TTF). As the discrepancy of $Q^2F_{\pi\gamma}(Q^2)$ data between the BaBar and Belle measurements has not been resolved yet,...
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  41. Dr Valery Lyubovitskij (Tuebingen University, Germany)
    22/09/2015, 17:30
    Oral contribution
    We present a high-quality description of the deuteron electromagnetic form factors in a soft-wall AdS/QCD approach [1]. We propose an effective action describing the dynamics of the deuteron in the presence of an external vector field. Based on this action the deuteron electromagnetic form factors are calculated, displaying the correct (1/Q2)**5 power scaling for large Q2 values. This...
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  42. Dr Jerzy A. Przeszowski (Faculty of Physics, University of Bialystok)
    22/09/2015, 17:30
    Oral contribution
    A new form of the light front Feynman propagators is proposed. It contains no energy denominators. Instead the dependence on the longitudinal subinterval x^2_L = 2 x^{+} x^{-} is explicit and a new formalism for doing the perturbative calculations is invented. These novel propagators are implemented for the one-loop scattering matrix for a massive scalar field. The consistency with...
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  43. 22/09/2015, 17:50
    See on Monday 21 for Abstracts
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  44. Dr Jaume Carbonell (CNRS/IPN Orsay)
    23/09/2015, 09:00
    Invited talk
    8.
    The solutions of the Bethe-Salpeter equation in Minkoswki space are mandatory for computing some physical quantities like elastic and transition form factors, scattering of-shell amplitudes etc. They are however plagued with the singularities of the free propagators, of the interaction kernel and of the amplitude itself making rather difficult its numerical computation. This difficulty...
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  45. Dr Gernot Eichmann (University of Giessen)
    23/09/2015, 09:30
    Invited talk
    8.
    The covariant three-body Faddeev approach and its application to nucleon and delta properties are briefly reviewed. I will discuss results for mass spectra as well as nucleon and delta elastic and transition form factors, together with the role of electromagnetic gauge invariance and vector-meson dominance. I will also talk about some recent work on Compton scattering, pion-cloud effects and...
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  46. Prof. Tobias Frederico (Instituto Tecnologico de Aeronautica)
    23/09/2015, 10:00
    Invited talk
    8.
    We report our attempts in extracting the Nakanishi weight function for a S-wave bound-state using a model for the Bethe-Salpeter amplitude from a given form of the weight function. Both the Bethe-Salpeter amplitude in Euclidean space and the valence light-front wave function are written in terms of the Nakanishi integral representation, and through that we formulate an inhomogeneous integral...
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  47. Dr Jean-Francois MATHIOT (Laboratoire de Physique Corpusculaire)
    23/09/2015, 10:30
    Invited talk
    8.
    The analysis of physical observables in terms of energy/momentum scales necessitates to disantangle spurious scales originating from the divergence of ill-defined integrals from the physical scales inherent to the dynamics of a given system. The use of finite field theories is thus of particular interest in this separation. We shall investigate this question in the light of the recently...
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  48. John Hiller (University of Minnesota-Duluth)
    23/09/2015, 11:45
    Invited talk
    9.
    As an extension of earlier work on QED, we construct a BRST-invariant Lagrangian for SU(N) Yang-Mills theory, regulated by the inclusion of massive Pauli-Villars (PV) gluons. The underlying gauge symmetry for massless PV gluons is generalized to accommodate the PV-index-changing currents that are required by the regularization. Auxiliary adjoint scalars are used, in a mechanism due to...
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  49. L. Martinovic
    23/09/2015, 12:15
    Oral contribution
    9.
    One of the apparent problems of light front field theory has been a lack of description of two-dimensional massless fields. We show how both the massless scalar and fermion fields can be recovered as massless limits of the two-dimensional massive fields and consistenly quantized without any loss of physical information. Bosonization of the ligh-front (LF) fermion field then follows in a...
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  50. Prof. Daya Shankar Kulshreshtha (Department of Physics and Astrophysics, University of Delhi, Delhi-110007, India)
    23/09/2015, 12:45
    Oral contribution
    9.
    In this talk, we study the light-front quantization of the restricted gauge theory of $~QCD_{2}~$ $~\grave{a}~$ la Cho et al., using Hamiltonian, path integral and BRST quantization procedures.
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  51. Alessandro Bacchetta (PV)
    24/09/2015, 09:00
    Invited talk
    10.
    I will review the current status of the extraction of Transverse Momentum Distributions (TMDs) from experimental data. We are gaining an ever increasing knowledge about TMDs, both unpolarized and polarized, but we are still far from a precise determination of these quantities. Central issues are currently related to the implementation of TMD evolution in the extractions. To make further...
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  52. Bernard Bakker (VU University)
    24/09/2015, 09:30
    Invited talk
    10.
    In scalar QED the number of Compton form factors is known to be five. The case where the incoming photon is virtual, namely produced by electron scattering, while the final photon is real, the physical amplitudes depend on only three of them. We study the sensitivity of the differential cross section to the subleading Compton form factors.
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  53. Mr Luciano Libero Pappalardo (FE)
    24/09/2015, 10:00
    Invited talk
    10.
    In the context of rapid theoretical developments in non-perturbative QCD, a formalism of Transverse Momentum Dependent parton distribution functions (TMDs) and of Generalized Parton Distributions (GPDs) was introduced in the last two decades, providing a more comprehensive multi-dimensional description of the nucleon. TMDs and GPDs allow in fact for complementary descriptions of the nucleon in...
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  54. Prof. Chueng-Ryong Ji (NCSU)
    24/09/2015, 10:30
    Invited talk
    10.
    While the leading nonanalytic behavior in chiral effective theory must be universal, there has been a puzzling factor 4/3 difference in the coefficient of the leading nonanalytic contribution to the vertex renormalization constant of the nucleon or equivalently that of the pion for more than a decade. We have recently resolved this lingering factor difference by carefully analyzing the vertex...
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  55. Dr Hervé Moutarde (Irfu, CEA-Saclay)
    24/09/2015, 11:45
    Invited talk
    11.
    In order to learn effectively from measurements of Generalised Parton Distributions (GPDs), it is desirable to compute them using a framework that can potentially connect empirical information with basic features of the Standard Model. We sketch an approach to such computations, based upon a rainbow-ladder (RL) truncation of QCD's Dyson-Schwinger equations and exemplified via the pion's...
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  56. Emanuele Pace (ROMA2)
    24/09/2015, 12:15
    Invited talk
    11.
    After the 12 GeV upgrade, several experiments involving 3He nuclear targets will be performed at JLab to extract information on the parton structure of the neutron. The parton transverse momentum distributions (TMDs) (see, e.g. [1,2]) in the neutron will be studied through polarized SIDIS experiments off 3He, where a high-energy pion is detected in coincidence with the scattered electron [3]....
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  57. Dr Harut Avakian (JLab)
    24/09/2015, 12:45
    Invited talk
    11.
    The quark-gluon dynamics manifests itself in a set of non-perturbative functions describing all possible spin-spin and spin-orbit correlations. The Transverse Momentum Dependent parton distributions (TMDs) and Generalized Parton Distributions (GPDs) carry information not only on the longitudinal but also on the transverse momentum and position of partons, providing rich and direct...
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  58. Jianhui Zhang (Regensburg University)
    24/09/2015, 14:30
    Invited talk
    12.
    Understanding the spin structure of the proton has been an important goal in hadron physics. One of the well-known spin sum rule, the Jaffe-Manohar sum rule, is motivated from a free-field expression of QCD angular momentum and has a natural partonic interpretation. However, this natural partonic sum rule exhibits a gauge dependence in its individual contributions (apart from the quark spin)....
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  59. Prof. Constantia Alexandrou (University of Cyprus & Cyprus Institute)
    24/09/2015, 15:00
    Invited talk
    12.
    Recent results on nucleon observables using simulations of Quantum Chromodynamics (QCD) with a range of quark masses that include their physical values are presented. We use a discretization of the theory known as twisted mass QCD, which allows for an automatic O(a^2) improvement without requiring improvement of the operators. The simulations use lattice spacings a<0.1fm and are ...
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  60. Prof. Oleg Teryaev (JINR)
    24/09/2015, 15:30
    Invited talk
    12.
    The Radon transform applications for relations between various light-cone distributions is considered. The contributions of different channels to the inverse Radon transform for Double Distributions are extracted. The relations between fracture and dihadron fragmentation functions are analyzed. The transverse momentum dependencies for exclusive and semi-inclusive processes are compared.
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  61. Ms Kelly Chiu (SLAC)
    24/09/2015, 16:30
    Oral contribution
    In this work, we define a modified non-local conformal transformation compatible with BRST formalism for $U(1)$ gauge field, which is a symmetry of the Maxwell's theory in any dimension. We prove the invariance by explicitly showing that the gauge invariant transverse two point function, the classical action, and equation of motion are unchanged under such transfomation.
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  62. Dr Silvia Pisano (LNF)
    24/09/2015, 16:30
    Oral contribution
    Deeply-Virtual Compton scattering provides the cleanest access to the 3D imaging of the nucleon structure encoded in the Generalized Parton Distributions, that correlate the fraction of the total nucleon momentum carried by a constituent to its position in the transverse plane. Besides the information on the spatial imaging of the nucleon, GPDs provide an access, through the Ji relation, to...
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  63. Dr Usha Kulshreshtha (Department of Physics, Kirori Mal College, University of Delhi, Delhi-110007, India)
    24/09/2015, 16:50
    Oral contribution
    In this talk, we study the light-front quantization of the vector Schwinger model with photon mass term in Faddeevian Regularization, describing two-dimensional electrodynamics with mass-less fermions but with a mass term for the $ U(1)$ gauge field \cite{13}-\cite{15}. This theory is seen to be gauge-non-invariant (GNI). We then construct a gauge-invariant (GI) theory corresponding to this...
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  64. Dr Xiaonu Xiong (INFN, Sezione di Pavia, Pavia, 27100)
    24/09/2015, 16:50
    Oral contribution
    Recent researches showed that the light-cone parton distributions can be accessed by investigating the quasi distributions which are space-like correlation functions, hence can be directly simulated on the lattice. In this talk, I will show the one-loop matching between the light-cone and quasi PDFs, GPDs. The matching condition is essential to extract the light-cone distribution from the...
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  65. Sophia Chabysheva (University of Minnesota-Duluth)
    24/09/2015, 17:10
    Oral contribution
    We extend earlier work on fully symmetric polynomials for three-boson wave functions to arbitrarily many bosons and apply these to a light-front analysis of the low-mass eigenstates of $\phi^4$ theory in 1+1 dimensions. The basis-function approach allows the resolution in each Fock sector to be independently optimized, which can be more efficient than the preset discrete Fock states in DLCQ. ...
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  66. Dr Miguel Echevarria (Nikhef / VU University Amsterdam)
    24/09/2015, 17:10
    Oral contribution
    The limit of high gluon density is currently under active investigation, both from the theoretical and the experimental side, since gluons play an increasingly important role as the energy of the relevant scattering process increases. Thus it is our aim to better understand this limit in order to get valuable information on the 3-dimensional structure of hadrons. In this talk I will analyze...
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  67. Mr Andrea Signori (VU University Amsterdam / Nikhef)
    24/09/2015, 17:30
    Oral contribution
    Production of quarkonia bound states from hadronic collisions can be a useful handle to map the probability density distributions for gluons inside protons. We derive the factorization theorem for the pT-spectrum of color-singlet quarkonia production in terms of gluon transverse-momentum-dependent parton distribution functions (TMD PDFs). With this tool we predict cross sections up to NNLL...
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  68. Mr Henry Lamm (Arizona State University)
    24/09/2015, 17:30
    Oral contribution
    The true muonium (μ^+μ^-) bound state presents an interesting test of light-cone quantization techniques. In addition to the standard problems of solving these non-perturbative calculations, true muonium requires correct treatment of e^+e^- Fock state contributions. Having previously produced a crude model of true muonium using the method of iterated resolvents [1], current work has focused...
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  69. Dr Frederik Van der Veken (University of Antwerp)
    24/09/2015, 17:50
    Oral contribution
    The Wilson line in a TMD is needed for gauge invariance, but quantum field theory lays no restriction on the specific path layout except for its endpoints. However, there is no reason to assume that different path structures would lead to equivalent results. Care has to be taken when splitting complicated structures into separate path segments, especially when the path contains obstructions...
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  70. 24/09/2015, 18:10
    See on Monday 21 for Abstracts
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  71. Prof. Gunnar Bali Bali (University of Regensburg)
    25/09/2015, 09:00
    Invited talk
    13.
    I review recent hadron structure results of the Regensburg group.
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  72. Dr Patrizia Rossi (Jefferson Lab)
    25/09/2015, 09:30
    Invited talk
    13.
    The Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab comprise a unique facility for nuclear physics research whose upgrade is presently underway, with completion expected in 2017. The upgraded facility will accelerate electron beams to 11 GeV for experiments in the existing Halls A, B and C. In addition, a 12 GeV beam can be...
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  73. Dr Marco Battaglieri (Istituto Nazionale di Fisica Nucleare)
    25/09/2015, 10:00
    Invited talk
    13.
    In the last few years interest for Light Dark Matter (LDM) in the MeV - GeV range has been increasingly growing. Direct detection of non-relativistic dark matter particles from the Galactic halo mainly focused to higher masses(> 10 GeV) being insensitive to few-GeV or lighter DM, whose nuclear scattering transfers invisibly small kinetic energy to a recoiling nucleus. On the other hand...
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  74. Franco Bradamante (TS)
    25/09/2015, 11:15
    Invited talk
    14.
    COMPASS is a fixed target experiment at the CERN SPS taking data since 2002. A major part of the COMPASS program at CERN is dedicated to the investigation of the 3 dimensional structure of the nucleon which can be reached measuring the spin and transverse momentum dependent distributions (TMDs) and generalized parton distributions (GPDs). TMDs have been investigated at COMPASS in...
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  75. James Vary (Iowa State University)
    25/09/2015, 11:45
    Invited talk
    14.
    Light-front Hamiltonian field theory has advanced to the stage of becoming a viable non-perturbative method for solving forefront problems in strong interaction physics. Physics drivers include hadron mass spectroscopy, generalized parton distribution functions, spin structures of the hadrons, inelastic strength functions, hadronization, particle production by strong external time-dependent...
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  76. Prof. Stanley Brodsky (SLAC National Accelerator Laboratory, Stanford University)
    25/09/2015, 12:15
    Invited talk
    14.
    Light-front holography provides a precise relation between the bound-state amplitudes in the fifth dimension of AdS space and the boost-invariant light-front wavefunctions describing the internal structure of hadrons in physical space-time. The resulting valence Fock-state wavefunctions of the light-front QCD Hamiltonian satisfy a relativistic equation of motion, analogous to the...
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  77. Alfredo Suzuki (Instituto de Fisica Teorica Universidade Estadual Paulista)
    Oral contribution
    In a recent work\cite{Sales} we demonstrated an interesting result about the properties of tunneling time in the light front with the help of phase time. The question we may pose is: What do we understand as a tunneling time? Since the quantum system goes across a region within the potential that is forbidden in classical physics, we are interested in knowing how long this system takes to do...
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